Improper sanitization of LDFLAGS with embedded spaces in go command with cgo in cmd/go
The go command may execute arbitrary code at build time when using cgo. This may occur when running "go get" on a malicious module, or when running any other command which builds untrusted code. This is can by triggered by linker flags, specified via a "#cgo LDFLAGS" directive. Flags containing embedded spaces are mishandled, allowing disallowed flags to be smuggled through the LDFLAGS sanitization by including them in the argument of another flag. This only affects usage of the gccgo compiler.
Improper handling of non-optional LDFLAGS in go command with cgo in cmd/go
The go command may execute arbitrary code at build time when using cgo. This may occur when running "go get" on a malicious module, or when running any other command which builds untrusted code. This is can by triggered by linker flags, specified via a "#cgo LDFLAGS" directive. The arguments for a number of flags which are non-optional are incorrectly considered optional, allowing disallowed flags to be smuggled through the LDFLAGS sanitization. This affects usage of both the gc and gccgo compilers.
Unsafe behavior in setuid/setgid binaries in runtime
On Unix platforms, the Go runtime does not behave differently when a binary is run with the setuid/setgid bits. This can be dangerous in certain cases, such as when dumping memory state, or assuming the status of standard i/o file descriptors. If a setuid/setgid binary is executed with standard I/O file descriptors closed, opening any files can result in unexpected content being read or written with elevated privileges. Similarly, if a setuid/setgid program is terminated, either via panic or signal, it may leak the contents of its registers.
The go command may generate unexpected code at build time when using cgo. This may result in unexpected behavior when running a go program which uses cgo. This may occur when running an untrusted module which contains directories with newline characters in their names. Modules which are retrieved using the go command, i.e. via "go get", are not affected (modules retrieved using GOPATH-mode, i.e. GO111MODULE=off, may be affected).
Calling any of the Parse functions on Go source code which contains //line directives with very large line numbers can cause an infinite loop due to integer overflow.
Backticks not treated as string delimiters in html/template
Templates do not properly consider backticks (`) as Javascript string delimiters, and do not escape them as expected. Backticks are used, since ES6, for JS template literals. If a template contains a Go template action within a Javascript template literal, the contents of the action can be used to terminate the literal, injecting arbitrary Javascript code into the Go template. As ES6 template literals are rather complex, and themselves can do string interpolation, the decision was made to simply disallow Go template actions from being used inside of them (e.g. "var a = {{.}}"), since there is no obviously safe way to allow this behavior. This
Excessive memory allocation in net/http and net/textproto
HTTP and MIME header parsing can allocate large amounts of memory, even when parsing small inputs, potentially leading to a denial of service. Certain unusual patterns of input data can cause the common function used to parse HTTP and MIME headers to allocate substantially more memory than required to hold the parsed headers. An attacker can exploit this behavior to cause an HTTP server to allocate large amounts of memory from a small request, potentially leading to memory exhaustion and a denial of service. With fix, header parsing now correctly allocates only the memory required to hold parsed headers.
Excessive resource consumption in net/http, net/textproto and mime/multipart
Multipart form parsing can consume large amounts of CPU and memory when processing form inputs containing very large numbers of parts. This stems from several causes: 1. mime/multipart.Reader.ReadForm limits the total memory a parsed multipart form can consume. ReadForm can undercount the amount of memory consumed, leading it to accept larger inputs than intended. 2. Limiting total memory does not account for increased pressure on the garbage collector from large numbers of small allocations in forms with many parts. 3. ReadForm can allocate a large number of short-lived buffers, further increasing pressure on the garbage collector. The combi
Incorrect calculation on P256 curves in crypto/internal/nistec
The ScalarMult and ScalarBaseMult methods of the P256 Curve may return an incorrect result if called with some specific unreduced scalars (a scalar larger than the order of the curve). This does not impact usages of crypto/ecdsa or crypto/ecdh.
Denial of service via crafted HTTP/2 stream in net/http and golang.org/x/net
A maliciously crafted HTTP/2 stream could cause excessive CPU consumption in the HPACK decoder, sufficient to cause a denial of service from a small number of small requests.
Large handshake records may cause panics in crypto/tls. Both clients and servers may send large TLS handshake records which cause servers and clients, respectively, to panic when attempting to construct responses. This affects all TLS 1.3 clients, TLS 1.2 clients which explicitly enable session resumption (by setting Config.ClientSessionCache to a non-nil value), and TLS 1.3 servers which request client certificates (by setting Config.ClientAuth >= RequestClientCert).
A denial of service is possible from excessive resource consumption in net/http and mime/multipart. Multipart form parsing with mime/multipart.Reader.ReadForm can consume largely unlimited amounts of memory and disk files. This also affects form parsing in the net/http package with the Request methods FormFile, FormValue, ParseMultipartForm, and PostFormValue. ReadForm takes a maxMemory parameter, and is documented as storing "up to maxMemory bytes +10MB (reserved for non-file parts) in memory". File parts which cannot be stored in memory are stored on disk in temporary files. The unconfigurable 10MB reserved for non-file parts is excessively
Excessive memory growth in net/http and golang.org/x/net/http2
An attacker can cause excessive memory growth in a Go server accepting HTTP/2 requests. HTTP/2 server connections contain a cache of HTTP header keys sent by the client. While the total number of entries in this cache is capped, an attacker sending very large keys can cause the server to allocate approximately 64 MiB per open connection.
Unsanitized NUL in environment variables on Windows in syscall and os/exec
Due to unsanitized NUL values, attackers may be able to maliciously set environment variables on Windows. In syscall.StartProcess and os/exec.Cmd, invalid environment variable values containing NUL values are not properly checked for. A malicious environment variable value can exploit this behavior to set a value for a different environment variable. For example, the environment variable string "A=B\x00C=D" sets the variables "A=B" and "C=D".
Incorrect sanitization of forwarded query parameters in net/http/httputil
Requests forwarded by ReverseProxy include the raw query parameters from the inbound request, including unparsable parameters rejected by net/http. This could permit query parameter smuggling when a Go proxy forwards a parameter with an unparsable value. After fix, ReverseProxy sanitizes the query parameters in the forwarded query when the outbound request's Form field is set after the ReverseProxy. Director function returns, indicating that the proxy has parsed the query parameters. Proxies which do not parse query parameters continue to forward the original query parameters unchanged.
Unbounded memory consumption when reading headers in archive/tar
Reader.Read does not set a limit on the maximum size of file headers. A maliciously crafted archive could cause Read to allocate unbounded amounts of memory, potentially causing resource exhaustion or panics. After fix, Reader.Read limits the maximum size of header blocks to 1 MiB.
In net/http in Go before 1.18.6 and 1.19.x before 1.19.1, attackers can cause a denial of service because an HTTP/2 connection can hang during closing if shutdown were preempted by a fatal error.
Panic when decoding Float and Rat types in math/big
A too-short encoded message can cause a panic in Float.GobDecode and Rat GobDecode in math/big in Go before 1.17.13 and 1.18.5, potentially allowing a denial of service.
Session tickets lack random ticket_age_add in crypto/tls
Non-random values for ticket_age_add in session tickets in crypto/tls before Go 1.17.11 and Go 1.18.3 allow an attacker that can observe TLS handshakes to correlate successive connections by comparing ticket ages during session resumption.
Indefinite hang with large buffers on Windows in crypto/rand
Infinite loop in Read in crypto/rand before Go 1.17.11 and Go 1.18.3 on Windows allows attacker to cause an indefinite hang by passing a buffer larger than 1 << 32 - 1 bytes.